The invention relates to a blood testing apparatus for determining an analyte, such as fructosamine, lactate, cholesterol, specifically glucose, from minimal quantities amounts of blood extracted immediately prior from a user.
The invention deals with blood testing apparatus of the kind that are configured with a membrane-like test means defining a field of measurement, said test means being wetted with the minimal amount of blood extracted and including test reagents, having an evaluation device comprising electronics working optically, preferably using reflectance analysis, or electronically and having a display device, where the aforementioned components form a complete system which can be manipulated as a single apparatus.
A diagnostic apparatus of this type is known from U.S. Pat. No. 4,787,398. This blood glucose monitoring apparatus comprises a housing structure with a push-rod arrangement to actuate a lancing element and having an evaluation device and a display device. For each measurement, a replaceable unit must be positioned in the housing structure, comprising the lancet and a test means to be wetted with blood in the form of a test strip. This replaceable unit is discarded after each use.
Using this as the point of departure, the object of the present invention is to further develop a blood testing apparatus which has fewer components to be manipulated individually and is thus easier to operate and more user friendly.
A blood testing apparatus known from EP 0 449 525 A1 similarly comprises an integral release device for a lancing element. Before each use, a new lancing element has to be manually inserted into the release device as part of the blood extraction device and then a test strip has to be inserted into the apparatus.
U.S. Pat. No. 4,627,445 shows a complete system for a glucose measuring apparatus in the aforesaid sense. But before each measurement a new replaceable unit of lancing element and test means has to be assembled to a body and removed afterwards.
U.S. Pat. No. 5,951,492 shows a similar device. According to this publication, a disposable unit comprises a capillary tube on the upper end of which a test strip is provided which is exposed to the minimal quantity of blood extracted. The capillary tube is configured at its lower end with a lancing element. Again, before and after each measurement a new disposable unit of the type just described must be installed or removed. According to a further embodiment, a transverse slot is provided in the area of the face of the apparatus facing the user, through which a porous test membrane with a carrier can be inserted, which is then penetrated by the lancing element in the lancing procedure.
According to one embodiment, U.S. Pat. No. 5,971,941 shows a complete system in the aforesaid sense, where a cartridge with unused srip-like test means is inserted into a housing and a suitable test means can then be brought into a suitable operating position by means of a driver. Through a triggering device, which forms part of the blood extraction device, a lance contained in a suitable test strip is urged outward by mean of a pushrod to pierce the surface of the user's skin so that capiliary blood can be obtained for analysis. More detailed information on how the analysis is performed cannot be obtained from this publication. According to a further embodiment described in this publication, a cylindrical disposable attachment or insert is descried which has a lancet and a tablet-shaped test membrane with an opening for the lancing device. This attachment or insert is then inserted into a recess of a pushrod arrangement which forces the lancing element outward to extract blood. Once again, before and after each test procedure the disposable unit must be installed or removed.